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The transitional nucleus 131Xe is investigated after multinucleon transfer (MNT) in the 136Xe+208Pb and 136Xe+238U reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and as an elusive reaction product in the fusion-evaporation reaction 124Sn(11B,p3n) 131Xe employing the HORUS γ-ray array coupled to a double-sided silicon strip detector (DSSSD) at the University of Cologne, Germany. The level scheme of 131Xe is extended to 5 MeV. A pronounced backbending is observed at ~ω ≈ 0.4 MeV along the negative-parity one-quasiparticle νh11/2(α = −1/2) band. The results are compared to the high-spin systematics of the Z = 54 isotopes and the N = 77 isotones. Large-scale shell-model calculations (LSSM) employing the PQM130, SN100PN, GCN50:82, SN100-KTH and a realistic effective interaction reproduce the experimental findings and provide guidance to elucidate the structure of the high-spin states. Further calculations in 129−132Xe provide insight into the changing nuclear structure along the Xe chain towards the N = 82 shell closure. Proton occupancy in the π 0h11/2 orbital is found to be decisive for the description of the observed backbending phenomenon.

Lifetimes of excited states in the neutron-deficient nucleus $^{61}\mathrm{Zn}$ were measured employing the recoil-distance Doppler-shift (RDDS) and the electronic fast-timing methods at the University of Cologne. The nucleus of interest was populated as an evaporation residue in $^{40}\mathrm{Ca}(^{24}\mathrm{Mg},n2p)^{61}\mathrm{Zn}$ and $^{58}\mathrm{Ni}(\ensuremath{\alpha},n)^{61}\mathrm{Zn}$ reactions at 67 and 19 MeV, respectively. Five lifetimes were measured for the first time, including the lifetime of the $5/{2}_{1}^{\ensuremath{-}}$ isomer at 124 keV. Short lifetimes from the RDDS analysis are corrected for Doppler-shift attenuation (DSA) in the target and stopper foils. Ambiguous observations in previous measurements were resolved. The obtained lifetimes are compared to predictions from different sets of shell-model calculations in the $fp$, ${f}_{5/2}p{g}_{9/2}$, and multishell $fp\text{\ensuremath{-}}{g}_{9/2}{d}_{5/2}$ model spaces. The band built on the $9/{2}_{1}^{+}$ state exhibits a prolate deformation with $\ensuremath{\beta}\ensuremath{\approx}0.24$. Especially, the inclusion of cross-shell excitation into the $1{d}_{5/2}$ orbital is found to be decisive for the description of collectivity in the first excited positive-parity band.

Objective:To determine signs and symptoms for superior canal dehiscence syndrome caused by the superior petrosal sinus.Methods:A review of the English-language literature on PubMed and Embase databases was conducted, in addition to a multi-centre case series report.Results:The most common symptoms of 17 patients with superior petrosal sinus related superior canal dehiscence syndrome were: hearing loss (53 per cent), aural fullness (47 per cent), pulsatile tinnitus (41 per cent) and pressure-induced vertigo (41 per cent). The diagnosis was made by demonstration of the characteristic bony groove of the superior petrosal sinus and the ‘cookie bite’ out of the superior semicircular canal on computed tomography imaging.Conclusion:Pulsatile tinnitus, hearing loss, aural fullness and pressure-induced vertigo are the most common symptoms in superior petrosal sinus related superior canal dehiscence syndrome. Compared to superior canal dehiscence syndrome caused by the more common apical location of the dehiscence, pulsatile tinnitus and exercise-induced vertigo are more frequent, while sound-induced vertigo and autophony are less frequent. There is, however, considerable overlap between the two subtypes. The distinction cannot as yet be made on clinical signs and symptoms alone, and requires careful analysis of computed tomography imaging.

The high-spin structures of the N = 81 isotones 135Xe and 137Ba are investigated after multinucleontransfer (MNT) and fusion-evaporation reactions. Both nuclei are populated in (i) 136Xe+238U and (ii) 136Xe+208Pb MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii), in the 136Xe+198Pt MNT reaction employing the -ray array GAMMASPHERE in combination with the gas detector array Chico, and (iv) via a 11B+130Te fusion-evaporation reaction. The high-spin level schemes of 135Xe and 137Ba are considerably extended to higher energies. The 2058-keV (19=2 ) state in 135Xe is identified as an isomer, completing the systematics for the N = 81 isotones. Its half-life is measured to be 8.6(10) ns, corresponding to a transition probability of B(E2; 19=2 ! 15=2 ) = 0:539(69) W.u. Latest shell model calculations considering 132Sn as a closed core reproduce the experimental findings and provide guidance to the interpretation of the new levels. The experimentally deduced reduced quadrupole transition probabilities of the isomeric states are compared to shell-model predictions.

Lifetimes of the 2 1 + states in 44Ti, 48,50Cr, and 52Fe were determined with high accuracy exploiting the recoil distance Doppler-shift method. The reduced E2 transition strengths of 44Ti and 52Fe differ considerably from previously known values. A systematic increase in collectivity is found for the N = Z nuclei compared to neighboring isotopes. The B ( E2 ) values along the Ti, Cr, and Fe isotopic chains are compared to shell-model calculations employing established interactions for the 0 f 1 p shell, as well as a novel effective shell-model Hamiltonian starting from a realistic nucleon–nucleon potential. The theoretical approaches underestimate the B ( E2 ) values for the lower-mass Ti isotopes. Strong indication is found for particle-hole cross-shell configurations, recently corroborated by similar results for the neighboring isotone 42Ca.

Excited states with intermediate and high spins in $^{33}\mathrm{P}$ and $^{33}\mathrm{S}$ have been populated using the $^{26}\mathrm{Mg}(^{13}\mathrm{C},np\ensuremath{\alpha})$ and $^{26}\mathrm{Mg}(^{13}\mathrm{C},2n\ensuremath{\alpha})$ fusion-evaporation reactions. The level schemes of both nuclei have been considerably extended. Utilizing $\ensuremath{\gamma}\ensuremath{\gamma}$ angular correlations the spin-parity assignment of the new excited states in $^{33}\mathrm{P}$ has been investigated. The experimentally determined results from both nuclei were compared to $0\ensuremath{\hbar}\ensuremath{\omega}$ and $1\ensuremath{\hbar}\ensuremath{\omega}$ truncated p-sd-pf shell-model calculations utilizing the PSDPF interaction, showing a very good agreement between experiment and theory.

Background: Shell-model calculations crucially depend on the residual interaction used to approximate the nucleon-nucleon interaction. Recent improvements to the empirical universal $sd$ interaction (USD) describing nuclei within the $sd$ shell yielded two new interactions---USDA and USDB---causing changes in the theoretical description of these nuclei.Purpose: Transition matrix elements between excited states provide an excellent probe to examine the underlying shell structure. These observables provide a stringent test for the newly derived interactions. The nucleus $^{26}\mathrm{Na}$ with 7 valence neutrons and 3 valence protons outside the doubly-magic ${}^{16}\mathrm{O}$ core is used as a test case.Method: A radioactive beam experiment with $^{26}\mathrm{Na}$ (${T}_{1/2}=1,07s$) was performed at the REX-ISOLDE facility (CERN) using Coulomb excitation at safe energies below the Coulomb barrier. Scattered particles were detected with an annular Si detector in coincidence with $\ensuremath{\gamma}$ rays observed by the segmented MINIBALL array. Coulomb excitation cross sections of the beam have been obtained by normalization to the well known Coulomb excitation cross sections of the $^{104}\mathrm{Pd}$ target.Results: The observation of three $\ensuremath{\gamma}$-ray transitions in $^{26}\mathrm{Na}$ together with available spectroscopic data allows us to determine $E2$- and $M1$-transitional matrix elements. Results are compared to theoretical predictions.Conclusion: The improved theoretical description of $^{26}\mathrm{Na}$ could be validated. Remaining discrepancies between experimental data and theoretical predictions indicate the need for future experiments and possibly further theoretical improvements.

Objective Recent developments in bone conduction hearing systems have seen the introduction of transcutaneous devices comprising of magnetic components. Our aim was to identify the number of children implanted with a traditional, non-magnetic percutaneous bone anchored hearing implant (BAHI) who would not have been eligible for a transcutaneous implant based on magnetic resonance imaging (MRI) need. Methods A retrospective case review of 206 children who had a percutaneous BAHI at the Birmingham Children's Hospital (January 2009–October 2012) for auditory rehabilitation. Results Twenty-eight percent (56/206) of children required at least one MRI scan after receiving a BAHI and 10 percent of patients (20/206) required two or more MRI scans. The main indication for MRI scanning was for neurological co-morbidities; a MRI brain was the most common scan performed. Conclusion Although transcutaneous hearing devices/middle ear implants have their clear benefits, it may be argued that these relatively more invasive surgical procedures may not be the best option for the child who will require MRI scanning at some point in the future. Clinicians should be mindful of any need for MRI scanning when considering implant choices in the pediatric population.

Seidlitz, M., et all ; 10 pags. ; 9 figs. ; 1 tab. ; PACS number(s): 21.60.Cs, 23.20.Js, 25.70.De, 29.38.Gj, Nuclear shell evolution in neutron-rich Na nuclei around N=20 was studied by determining reduced transition probabilities, i.e., B(E2) and B(M1) values, in order to map the border of the island of inversion. To this end Coulomb-excitation experiments, employing radioactive 29,30Na beams with a final beam energy of 2.85 MeV/nucleon, were performed at REX-ISOLDE, CERN. De-excitation γ rays were detected by the MINIBALL γ-ray spectrometer in coincidence with scattered particles in a segmented Si detector. Transition probabilities to excited states were deduced. The measured B(E2) values agree well with shell-model predictions, supporting the idea that in the Na isotopic chain the ground-state wave function contains significant intruder admixture already at N=18, with N=19 having an almost pure two-particle-two-hole deformed ground-state configuration. © 2014 American Physical Society., This work has been supported by the German BMBF under Contracts No. 06K-167, No. 06KY205I, No. 06DA9036I, No. 06MT9156, No. 05P09PKCI5, No. 05P12PKFNE, No. 05P12RDCIA, and No. 05P12RDCIB, by the FWOVlaanderen (Belgium), by the IAP Belgian Science Policy (BriX network (P7/12)), by the UK Science and Technology Funding Council, by the EUROpean Nuclear Structure Integrated Infrastructure Initiative (EURONS, RII3-CT-2004- 506065), and by the European Nuclear Science and Applications Research (ENSAR) under Project No. 262010.

We have studied the aggregation behavior of polyethylene−poly(ethylenepropylene) (PE−PEP) diblock copolymers dissolved in decane. For this purpose PE−PEP diblock copolymers of various molecular weights, compositions, and degrees of deuteration were synthesized via an anionic route. The structure and morphology of the aggregates was studied by small angle neutron scattering varying both the contrast as well as the polymer labeling. We found a hierarchy of structures: The PE component crystallizes in lamellar sheets (thickness 40−80 A) surrounded on both sides by a PEP brush which exhibits a close to parabolic density profile. Different aggregates form macroaggregates of needlelike shape with the PE lamellar planes in the long direction. This macroaggregation is well described by a paracrystalline structure factor. The structural parameters depending on composition and molecular weights can be well understood in terms of a free energy of formation based on a scaling model. A quantitative evaluation of the ...

Polymer brushes forming the outer shells of micellar aggregates of A–B diblock copolymers in a selective solvent allow for the observation of collective relaxational motions via neutron spin-echo spectroscopy. New neutron spin-echo investigations on planar PEB-brushes on the surface of crystalline PE-cores of platelet-like aggregates are reported. The data are discussed in comparison to a continuum model of the brush assuming a parabolic density profile, semidilute solution scaling relations for the elastic properties and friction coefficient. For the planar brush a full 3D solution of the model is accessible. The observed scattering from an isotropic sample is compatible with the continuum model with an added static fluctuation contribution.

A-B block copolymers in a selective solvent—good for the B-species and bad for the A-species—form micellar aggregates with a compact A-core with a corona (brush) of B «hairs» reaching into the solvent. Whereas polystyrene(PS)-polyisoprene(PI) in decane forms spherical micelles with a PS core of about 10 nm radius, polyethylene(PE)-polyethylenepropylene(PEP) forms micellar platelets, the shape of which is goverend by the habitus of PE crystallites forming the core. These planar aggregates have large (several hundred nanometers) lateral extension and a core thickness in the range of 10 nm. Both systems are model systems for polymer brushes, either on a spherical surface or planar. Neutron spin-echo experiments allow for the investigation of the dynamics of the brushes which reflects their viscoelastic properties. Results of neutron small-angle and spin-echo investigations are reported. The brush dynamics is explained using a model based on an idea of de Gennes describing the brush properties in terms of scaling relations for osmotic pressure and viscosity of a semi-dilute solution with inhomogeneous density.

Results from multicontrast SANS investigations of aggregates that form on cooling a solution of polyethylene(PE)–polyethylenepropylene(PEP) block copolymer in decane are reported. The PE-cores form extended crystalline platelets covered by a “brush” of PEP-“hairs” on both sides. Added wax (paraffin) is taken up by these aggregates. Decane may be considered as a model for diesel fuel and the waxes as contaminants in diesel fuel that crystallize at low temperatures and clog the filters of engines. It is explained why compounds of the PE–PEP family efficiently reduce the minimum temperature down to which these fuels may be used by directing the wax precipitation/nucleation into aggregates that are small enough to pass the filters.

Verschiedene Untersuchungen haben ethnische und geographische Unterschiede in der Knochendichte (BMD) und in der Inzidenz osteoporotischer Frakturen gezeigt [1]. Die Erhebung von regionalen Referenzdaten zur Knochendichte erscheint daher notwendig [2]. Obwohl die Bestimmung der Knochendichte eine Abschatzung des Frakturrisikos erlaubt [3], ist haufig die Diskriminierung zwischen normal und Osteoporose unzureichend.